A critically important aspect of building a new computer system is designing the low-level machine language, or instruction set, with which the computer can be instructed to do various things. As it turns out, this can be done before the computer itself is actually built. For example, we can write a Java program that emulates the yet-to-be-built computer, and then use it to emulate the execution of programs written in the new machine language. Such experiments can give us a good appreciation of the bare bone "look and feel" of the new computer, and lead to decisions that may well change and improve both the hardware and the language designs. Taking a similar approach, in this module we assume that the Hack computer and machine language have been built, and write some low-level programs using the Hack machine language. We will then use a supplied CPU Emulator (a computer program) to test and execute our programs. This experience will give you a taste of low-level programming, as well as a solid hands-on overview of the Hack computer platform.